JP3013728B2 - Control device for vehicle drive unit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle drive system, and more particularly to a control system for controlling a vehicle drive system to maintain a state ready for restart when the vehicle stops.

[0002]

2. Description of the Related Art Conventionally, in a vehicle drive system using an engine as a power source, fuel supply to the engine is automatically performed even when the vehicle is stopped for a short time in order to reduce fuel consumption and exhaust gas. In other words, control to stop the engine is performed in some vehicles with a manual transmission. Further, Japanese Patent Application Laid-Open No. 60-125538 proposes a technique for realizing such automatic stop and start of an engine in an automatic transmission.

[0003]

By the way, in the above-mentioned prior art, the fuel consumption and the exhaust gas can be reduced by stopping the engine. It is inevitable that starting will be slow compared to starting from the engine running state. This is because a predetermined time is required from when the engine is started to when the engine reaches a predetermined idling rotation or a rotation corresponding to the throttle opening. Further, in the case of an automatic transmission, it is customary to drive an oil pump by rotation of the engine and operate a hydraulic servo for achieving a gear position including a forward clutch with hydraulic pressure generated by the oil pump. If the engine is temporarily stopped by the control, the rise of the hydraulic pressure occurs a little later than the rise of the engine rotation after the restart, so that the start delay is further increased due to the time lag of the hydraulic pressure transmission.

[0004] Therefore, the present invention is to improve fuel efficiency and reduce exhaust gas while preventing the above-mentioned backlash at the time of starting by maintaining the rotation state of the engine while stopping the supply of fuel to the engine when the vehicle is stopped. It is an object of the present invention to provide a control device for a vehicle drive device capable of reducing the amount of power.

[0005]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides an engine provided with a fuel supply device for supplying fuel required according to the running conditions of a vehicle, and an output shaft of the engine. An automatic transmission having a start clutch connected to the wheels via a fluid transmission, and transmitting hydraulic power from the engine to the wheels, and a hydraulic servo for engaging the start clutch. And a control device for controlling the engine, the automatic transmission mechanism, and the drive motor, the drive device driving the output shaft by the supply of the vehicle. A stop state detecting means for detecting whether the apparatus is in a stop state, a hydraulic control means for controlling supply of hydraulic pressure to the hydraulic servo, and a fuel supply device Fuel control means for controlling the supply, and drive control means for controlling the supply of current to the drive motor, when the stop state is detected by the stop state detection means, the hydraulic control means, The supply of hydraulic pressure to the hydraulic servo is reduced, the power transmission of the starting clutch is cut off, the fuel control means stops supply of fuel by the fuel supply device, and the drive control means supplies a current to the drive motor. And the driving motor is driven to maintain the rotation of the engine at an idling speed.

[0006]

According to the present invention, when the engine is idling and the vehicle is stopped, the supply of fuel is stopped. However, the engine is maintained at the idling speed by the drive motor and continues to rotate. By restarting the fuel supply at the time of starting, the engine can be quickly returned to the operating state. In addition, when the engine is in the rotating state, the hydraulic pressure of the automatic transmission mechanism is being generated, so that the rise of the hydraulic pressure is not delayed. Further, when the driving by the engine is restarted, the engine is already rotating, and it is possible to prevent the consumption of excess fuel at the time of restarting the engine as in the conventional case.

Further, in the present invention, in the above-mentioned stopped state, the starting clutch of the automatic transmission mechanism is in the power cutoff state. Therefore, as in the case where the starting clutch is engaged, the load on the output side of the clutch is reduced. Since no dragging or slippage of the fluid transmission device occurs, the driving force of the drive motor is reduced by that much, and power consumption for maintaining the engine rotation can be minimized. There is no need to increase the source.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. As conceptually shown in FIG. 1, the vehicle drive device includes an engine (E / G) 10 including a fuel supply device 11 that supplies a required fuel according to running conditions of the vehicle.
Having. The output shaft 12 of the engine 10 includes the engine 1
A starting clutch 21 for transmitting power from 0 to wheels (not shown), and a hydraulic servo 22 for engaging the starting clutch 21
Is connected via a fluid transmission device 30 which is a torque converter including a pump impeller 31, a turbine runner 32 and a stator 33 in this example. A drive motor 40 for driving the output shaft 12 by supplying current is connected to the output shaft 12 of the engine 10. Further, the drive device includes a control device 50 that controls the engine 10, the automatic transmission mechanism 20, and the drive motor 40.

The control device 50 includes a stop state detecting means 53 for detecting whether the vehicle is in a stopped state while the engine 10 is idling, a hydraulic control means 52 for controlling the supply of hydraulic pressure to the hydraulic servo 22, and a fuel supply. Fuel control means 51 for controlling the supply of fuel by the device 11;
Drive control means 54 for controlling the supply of current to

As shown in FIG. 2 as a block diagram showing the configuration of the vehicle drive unit, the control unit 50 is constituted by a microcomputer (ECU). , The fuel control means 51 and the drive control means 54 are provided as the program. Various sensors constituting the input means of the stop state detecting means 53 include a throttle opening sensor 14 for detecting a throttle opening (θ) in an intake system of the engine 10, a brake switch 70 which is turned on by depressing a brake pedal, an engine. , An engine rotation sensor 13 for detecting the output shaft speed (N _E ), a voltage sensor 61 for detecting the voltage (V _E ) of the battery 60, a shift position sensor 24 for detecting a selection range in the shift device of the automatic transmission mechanism 20, A vehicle speed sensor 25 detects a vehicle speed (V) from the rotation of the output shaft of the automatic transmission mechanism 20.

The drive motor 40 includes a permanent magnet rotor 41.
, A plurality of slots are formed, and a coil is wound around the stator 42. The rotor 41 is fixed to the output shaft 12, and the stator 42 is fixed to the case 29 of the automatic transmission mechanism 20. . Also, the automatic transmission mechanism 20
An oil pump 23 connected to the rotor 41 of the drive motor 40 and supplying hydraulic pressure to the hydraulic control device 26 of the automatic transmission mechanism 20 has a plurality of oil pumps 23 arranged on the output side from the starting clutch 21 in accordance with the range selection by the shift device. It has a speed change mechanism 27 that achieves the gear position. In the figure, reference numeral 80
Indicates a fuel tank.

Next, details of the control by the control device 50 will be described with reference to FIG. 2 and the flowchart of FIG. After the control is started, it is determined in the first step S1 whether or not the ignition is turned on for the first time. In this judgment,
When it is determined that the power is turned on for the first time, the process proceeds to step S2 for performing normal engine start, and when it is determined that the power is already turned on, the process proceeds to step S5.

In step S2, as an initial setting, automatic engine stop and start control (hereinafter, referred to as the subject of the present invention)
The flag F for identifying this control is set to 0. next,
In step S3, in order to start the engine (E / G) 10, the drive motor 40 is connected to the battery 60 until the engine 10 starts, and the engine 10 is driven as a starter. At this time, fuel corresponding to the throttle opening (θ) is supplied from the fuel supply device 11 to the intake system of the engine 10 by fuel injection or the like. When the start of the engine 10 is completed, the drive motor 40 is used as a generator in step S4, and the generated power is charged into the battery 60.

Steps S5 to S9 are processes for judging whether or not to execute automatic engine stop and start control (hereinafter referred to as main control) as a subject of the present invention. First, in step S5, it is confirmed that the battery voltage is equal to or higher than a specified value (usually, 12 V in a car or the like). When this voltage is less than the specified value, it is considered that the charging of the battery 60 is insufficient, and this control is not performed.
In the following steps S6 to S9, the shift position is the D range, the vehicle speed V is 0, the throttle opening θ
Is determined to be 0 or the brake switch 70 is on. When all of these conditions are satisfied, the vehicle is considered to be in a stopped state, and the process proceeds to step S10 to execute this control. If not, the process proceeds to step S15.

In step S10, it is determined by a flag F whether or not the present control is being executed. Since the flag F is initially 0, the flag F is set to 1 in the next step S11. In step S12 and thereafter, the operation according to the present control is started. In step S12, a signal is output to the hydraulic control device 26 so as to reduce the hydraulic pressure of the hydraulic servo 22 that disengages the start clutch 21 and cut off the power transmission. And
In step S13, the drive motor 40 is switched from the power generation state to the drive state. Further, the engine speed (N _E ) is detected from the engine speed sensor 13 and is controlled so as to reach a target engine speed (idling speed). Such control is continued until this control is completed. In step S14, a signal is output to the fuel supply device 11 to stop the fuel supply.

On the other hand, steps S5 to S
If the determination in Step 9 is negative, that is, if it is determined that the vehicle is in the running state, it is determined in Step S15 whether or not the main control has been executed by the flag F being 1 or not, and the main control has been executed. If so, the control end processing in steps S16 to S19 is performed; otherwise, the subsequent processing is skipped and the routine returns.

In step S16, the flag is set to "0".
Then, in step S17, the supply of the fuel is restarted, and the supply state is returned to the normal throttle opening degree or the like. Further, in step S18, the drive motor 40 is returned from the drive state to the power generation state. Finally, in step S19, the hydraulic pressure of the hydraulic servo 22 is returned to the normal state, and the power transmission by the starting clutch 21 is enabled.

In short, in this control device, when the stop state is detected by the stop state detecting means 53,
The hydraulic control unit 52 reduces the supply of hydraulic pressure to the hydraulic servo 22, shuts off the power transmission of the starting clutch 21, the fuel control unit 51 stops the supply of fuel to the fuel supply device 11, and the drive control unit 54 Performs control to maintain the rotation of the engine 10 at the idling rotational speed by supplying a current to the drive motor 40 to bring the drive motor 40 into a driving state.

Thus, according to the present embodiment, when the engine 10 is idling and the vehicle is stopped, the supply of fuel is stopped.
0 is maintained at the idling speed. Thus, the rotation of the engine 10 is maintained when the vehicle starts moving, so that when the fuel supply is restarted, it is possible to promptly shift to the engine driven state. Also, as described above, the engine 10
Is in a rotating state, the hydraulic pressure of the automatic transmission mechanism 20 is in a state of being generated, and the rise of the hydraulic pressure is not delayed. Further, when the driving by the engine 10 is restarted, the engine 10 continues to rotate, so that the control for temporarily increasing the fuel supply amount to facilitate the starting at the time of restarting as in the related art becomes unnecessary. This can also prevent consumption of extra fuel.

Further, in this embodiment, since the starting clutch 21 of the automatic transmission mechanism 20 is in the power cutoff state in the above-mentioned stopped state, the fluid transmission device 30 is slipped as when the starting clutch 21 is engaged. Since no driving force is required, the driving force is reduced by that amount, and power consumption can be suppressed. Therefore, it is not necessary to increase the power source for the driving motor 40.

As described above, the present invention has been described in detail with reference to the embodiments. However, the present invention can be embodied with various specific details changed within the scope of the claims. Further, in the above embodiment, the drive motor 40 is used as a power source for maintaining the engine rotation at the idling rotation when the vehicle is stopped, and functions as a starter at the time of starting the engine at the beginning of running of the vehicle. However, when the fluid transmission device 30 is provided with a lock-up clutch, control to further function as a regenerative brake at the time of engine reverse drive can be performed.

[Brief description of the drawings]

FIG. 1 is a block diagram conceptually showing a configuration of a vehicle drive device to which the present invention is applied.

FIG. 2 is a block diagram showing the configuration of the embodiment in accordance with the substance.

FIG. 3 is a flowchart showing a control process in the embodiment.

[Explanation of symbols]

 REFERENCE SIGNS LIST 10 engine 11 fuel supply device 12 output shaft 20 automatic transmission mechanism 21 starting clutch 22 hydraulic servo 30 fluid transmission device 40 drive motor 50 control device 51 fuel control means 52 hydraulic control means 53 stop state detection means 54 drive control means

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yoshihisa Yamamoto 10 Takane, Fujii-machi, Anjo, Aichi Prefecture Inside Aisin AW Co., Ltd. (72) Masaaki Nishida 10 Takane, Fujii-machi, Anjo, Aichi Prefecture Aisin・ AW Co., Ltd. (56) References JP-A-6-26372 (JP, A) JP-A-63-248936 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B60K 41/28 F02D 29/00 F02D 29/02 B60L 11/00

Claims (1)

(57) [Claims] 1. An engine having a fuel supply device for supplying fuel required according to a traveling condition of a vehicle, and an engine connected to an output shaft of the engine via a fluid transmission,
A starting clutch that transmits power from the engine to the wheels,
An automatic transmission mechanism having a hydraulic servo for engaging the starting clutch; a drive motor connected to an output shaft of the engine and driving the output shaft by supplying current; the engine, the automatic transmission mechanism, and the drive A control device for controlling a motor, wherein the control device detects a stop state detecting unit that detects whether the vehicle is in a stopped state while the engine is idling, and supplies hydraulic pressure to the hydraulic servo. Hydraulic control means for controlling;
Fuel control means for controlling the supply of fuel by the fuel supply device, and drive control means for controlling the supply of current to the drive motor, when a stop state is detected by the stop state detection means, The hydraulic control means reduces supply of hydraulic pressure to the hydraulic servo, cuts off power transmission of the starting clutch,
The fuel control unit stops the supply of fuel by the fuel supply device, and the drive control unit supplies an electric current to the drive motor to bring the drive motor into a driving state, thereby causing the rotation of the engine to idle. A control device for a vehicle drive device, wherein the control device is maintained at a number.